Astronomers now recognize 88 constellations. A memory aid I’ve used through the years is that there are the same number of constellations as keys on a full piano keyboard. Today’s star groups cover the sky with no overlaps and no gaps between them. This, however, is a fairly recent development. Before 1928, celestial mapmakers were free to populate the skies as they pleased, with only the mildest restraint placed upon them by astronomers and other...

In my last blog post , I presented a 25-question constellation trivia quiz. Here are the answers. 1) Serpens occupies two regions of sky. Ophiuchus the Serpent-bearer separates Serpens. 2) Unlike the Southern Cross, whose long axis points to the South Celestial Pole, the “False Cross” gives only bad directions. Two of its stars come from Carina (Iota and Epsilon) and Vela (Delta and Kappa). 3) Before astronomers formalized the constellation boundaries...

Recently, I stood in a foot of snow when the Fahrenheit temperature was barely in the teens. I dressed warmly (or so I thought), but I wasn’t doing anything physical, so the cold was biting at my extremities. Yes, I was observing. As much as I despise cold weather (see, for instance, my blog “ The weather gods hate me ”), there’s a lot to be said for observing during the winter. When the temperature dips well below freezing, the crunchy snow pack...

Last week, I blogged about my one-year anniversary. In that article, I began listing my favorite celestial objects in several categories. Following are the categories I didn't get to. Planetary nebula — The Ghost of Jupiter (NGC 3242) in Hydra. This bright planetary shows lots of detail through 8-inch telescopes, but in large instruments it's amazing. My wife first saw the Ghost through a 20-inch Newtonian reflector at 650x. She turned to...

This blog marks my one-year anniversary yakking about any astronomical subject that caught my fancy. Blogs were new at Astronomy in 2006, but blogging seemed like a great vehicle for covering lots of topics in a somewhat random manner. Now, many of our editors blog on a weekly basis. I will use this momentous occasion to give you an insight into who I am as an observer. Through the years, many of you have shared with me your favorite objects, observing...

Springer The definitive work on a famous list of deep-sky objects is now in print: The Herschel Objects, and how to observe them by James Mullaney (Springer, 2007). Why definitive? Because, in 1976, Mullaney was the first to propose an observing list based on Herschel's catalog. Mullaney packs an incredible amount of information into this 166-page book. He gives us a brief history of English astronomer Sir William Herschel (1738–1822), a list...